decrease the incidence of the rest of the airplane ????

The incidence of the airplane is the incidence of the wing. The AOA of the "rest of the airplane" would chance if the wing incidence is changed.

Incidence of the wing is the angle between the wing/fuselage centerline as is the incidence of the h.tail the angle to the fuselage centerline. Changing the incidence of the "rest of the airplane" gives the same change if you changed either part's angles.

And if you decrease the AOA (if you meant AOA instead of incidence) of the whole airplane (except the wing), you wind up decreasing the AOA of the h.tail.

If you "increase your wing incidence " you will change the AOA of the "rest of the airplane" but the result is to pitch the fuselage CL nose down more at cruise when the wing settles into giving the lift it has to give. And that's affected of course by the new drag on the fuselage and the new trim on the elevator you're going to need since the h.tail is at a different AOA.

Not sure what you want to say? Hard to follow stuff when new ways of describing things happen.